Ethernet doesn't come up because cloud-init doesn't configure the ethernet adapter

[BassMonkey]

Currently rpi-imager is only generating the wifi adapter in the network-config. At least with Ubuntu 22.04 and 22.10 it is necessary to also define the ethernet interface, otherwise it won't come up and get an IP via DHCP. Since most headless installs will rely on the rpi getting an IP address assigned via DHCP (or manually setting one, which is not yet possible at all with rpi-imager), we should add the following lines to the network-config file:

ethernets:
  eth0:
    dhcp4: true
    optional: true

It might also be a good idea to expose this in the GUI as a checkmark (e.g. "enable ethernet port with DHCP").

[MatthewCKelly]

I agree with this..